news - March 2020
Is it Muggy in Here?
We all have our personal preferences, but humidity that is too low or too high can cause problems.
By Bill Hensley
OUR SENSE OF SMELL CREATES STRONG MEMORIES, and one of my strongest childhood memories is the smell of my uncle Chester’s basement. I was a Southern California child of Midwest parents and after the seventh grade my family headed to Detroit and then to Cincinnati for an extended hot and muggy summer with relatives. The basement was what we might today call the “man cave” and the memorable smell was from the mixture of heat and humidity in a rather dark environment. It marked this California kid’s introduction to a magical machine that could actually pull water out of the air and fill up a tank that had to be drained daily — the dehumidifier.
As an adult, still in California, I spend a reasonable amount of energy adding humidity back into the air. Here in the Bay Area we experienced a rainless February, which followed a dry January. That seasonal waterfall at the end of the block has been reduced to a thirsty rock wall. Adding humidity back into our household’s air is turning into a ten month a year cycle.
Humidity, or the lack of it, is not just about wrestling with extremes; there is a target range that delivers healthful benefits to people and the homes in which we live. The Consumer Product Safety Commission recommends a humidity level between 30 and 50 percent and the Environmental Protection Agency recommends keeping humidity between 30 and 60 percent to reduce mold growth. This range is influenced by outdoor temperatures; colder outside temperatures necessitate lower indoor humidity levels to minimize window condensation.
We all have our personal preferences of what feels most comfortable, but humidity that is too low or too high can cause problems. Low humidity can lead allergy or asthma symptoms to worsen. Cold and flu viruses spread more rapidly and are more likely to result in sinus infections. And overly dry air can be bad for the home itself; wood in building materials and furniture needs moisture to remain vibrant and resist cracking. High indoor humidity can have negative effects as well, promoting mildew, mold, fungi and bacteria which can be harmful to the home and its inhabitants. The viruses that spread in low humidity can also flourish in high humidity environments.
Humidity is clearly one of the components of the indoor air ecosystem. Along with purification, ventilation and temperature control, the technology that drives the ecosystem seeks to maintain the appropriate balance and deliver healthy air to the home’s inhabitants. This enables more than just comfort, but a state of wellness. When the humidity is in the optimal range it also helps the furnace or air conditioner work more efficiently, resulting in cost savings.
Uncle Chester’s dehumidifier had two modes: on and off. Today’s dehumidifiers and humidifiers have humidity sensors that can trigger the on/off mode to maintain the right humidity level. Modern whole home humidifiers and dehumidifiers from manufacturers like Aprilaire integrate into the home’s HVAC system to maintain a healthy air environment. Humidity control can be managed through several Aprilaire programmable thermostats—and those from other manufacturers—with multiple sensors tracking and averaging humidity throughout the home. Of course, the HVAC system can be integrated into the smart home control system, to automate operation for the ultimate ease of use and comfort.
More than ever, the smart home is the healthy home. Air quality is an important consideration for designers and builders, the biophilic benefits from natural lighting and materials and indoor-outdoor “green” spaces will not be fully realized if the HVAC system is not delivering a balanced and healthy air.